The CIA is carrying out lethal drone strikes against al-Qa'ida militants inside Yemen from a remote base in Saudi Arabia, including one that killed US-born Anwar al-Awlaki.
Any operation by US military or intelligence officials inside Saudi Arabia is politically and religiously sensitive.
Al-Qa'ida and other militant groups have used the Gulf kingdom's close working relationship with US counterterrorism officials to stir up internal dissent against the Saudi regime.
The location of the Saudi base was revealed by The New York Times online.
The Associated Press first reported the construction of the base in June 2011 but withheld the exact location at the request of senior administration officials.